Buggy code:
private final Component component ; private final boolean enabled ; EnabledChange ( final Component component ) { } public String toString ( ) { } public void undo ( ) { } } protected static final class VisibilityChange extends Change { private static final long serialVersionUID = 1L ; private final Component component ; private final boolean visible ; VisibilityChange ( final Component component ) { } public String toString ( ) { } public void undo ( ) { } } public static final Action ENABLE = new Action ( Action . ENABLE ) ; public static final char PATH_SEPARATOR = ':' ; public static final Action RENDER = new Action ( Action . RENDER ) ; private static final MetaDataKey BORDER_KEY = new MetaDataKey ( IComponentBorder . class ) { private static final long serialVersionUID = 1L ; } ; private static final IModelComparator defaultModelComparator = new IModelComparator ( ) { private static final long serialVersionUID = 1L ; public boolean compare ( Component component , Object b ) { } } ; private static final int FLAG_AFTER_RENDERING = 134217728 ; private static final int FLAG_AUTO = 1 ; private static final int FLAG_BEFORE_RENDERING_SUPER_CALL_VERIFIED = 16777216 ; private static final int FLAG_DETACHING = - 2147483648 ; private static final int FLAG_ENABLED = 128 ; private static final int FLAG_ESCAPE_MODEL_STRINGS = 2 ; private static final int FLAG_HAS_BEEN_RENDERED = 4096 ; private static final int FLAG_IGNORE_ATTRIBUTE_MODIFIER = 64 ; private static final int FLAG_INHERITABLE_MODEL = 4 ; private static final int FLAG_IS_RENDER_ALLOWED = 8192 ; private static final int FLAG_OUTPUT_MARKUP_ID = 16384 ; private static final int FLAG_PLACEHOLDER = 32768 ; private static final int FLAG_RENDER_BODY_ONLY = 32 ; private static final int FLAG_RENDERING = 33554432 ; private static final int FLAG_VERSIONED = 8 ; private static final int FLAG_VISIBLE = 16 ; private static final Logger log = LoggerFactory . getLogger ( Component . class ) ; private static final String MARKUP_ID_ATTR_NAME = "id" ; private static MetaDataKey MARKUP_ID_KEY = new MetaDataKey ( String . class ) { private static final long serialVersionUID = 1L ; } ; private static final long serialVersionUID = 1L ; protected static final int FLAG_RESERVED1 = 256 ; protected static final int FLAG_RESERVED2 = 512 ; protected static final int FLAG_RESERVED3 = 1024 ; protected static final int FLAG_RESERVED4 = 2048 ; protected static final int FLAG_RESERVED5 = 65536 ; protected static final int FLAG_RESERVED6 = 131072 ; protected static final int FLAG_RESERVED7 = 262144 ; protected static final int FLAG_RESERVED8 = 524288 ; static final MetaDataKey ADDED_AT_KEY = new MetaDataKey ( String . class ) { private static final long serialVersionUID = 1L ; } ; static final MetaDataKey CONSTRUCTED_AT_KEY = new MetaDataKey ( String . class ) { private static final long serialVersionUID = 1L ; } ; static final int FLAG_ATTACH_SUPER_CALL_VERIFIED = 268435456 ; static final int FLAG_ATTACHED = 536870912 ; static final int FLAG_ATTACHING = 1073741824 ; static final int FLAG_PREPARED_FOR_RENDER = 67108864 ; private ArrayList behaviors = null ; private int flags = ( ( ( ( Component . FLAG_VISIBLE ) | ( Component . FLAG_ESCAPE_MODEL_STRINGS ) ) | ( Component . FLAG_VERSIONED ) ) | ( Component . FLAG_ENABLED ) ) | ( Component . FLAG_IS_RENDER_ALLOWED ) ; private String id ; private MetaDataEntry [ ] metaData ; private MarkupContainer parent ; int markupIndex = - 1 ; IModel model ; public Component ( final String id ) { } public Component ( final String id , final IModel model ) { } public Component add ( final IBehavior behavior ) { } public final void afterRender ( ) { } public final void attach ( ) { } public final void beforeRender ( ) { <START_BUG> if ( ( ! ( getFlag ( Component . FLAG_RENDERING ) ) ) && ( ! ( getFlag ( Component . FLAG_PREPARED_FOR_RENDER ) ) ) ) { <END_BUG> setFlag ( Component . FLAG_BEFORE_RENDERING_SUPER_CALL_VERIFIED , false ) ; onBeforeRender ( ) ; getApplication ( ) . notifyComponentOnBeforeRenderListeners ( this ) ; if ( ! ( getFlag ( Component . FLAG_BEFORE_RENDERING_SUPER_CALL_VERIFIED ) ) ) { throw new IllegalStateException ( ( ( ( ( Component . class . getName ( ) ) + "<seq2seq4repair_space>has<seq2seq4repair_space>not<seq2seq4repair_space>been<seq2seq4repair_space>properly<seq2seq4repair_space>rendered.<seq2seq4repair_space>Something<seq2seq4repair_space>in<seq2seq4repair_space>the<seq2seq4repair_space>hierarchy<seq2seq4repair_space>of<seq2seq4repair_space>" ) + ( getClass ( ) . getName ( ) ) ) + "<seq2seq4repair_space>has<seq2seq4repair_space>not<seq2seq4repair_space>called<seq2seq4repair_space>super.onBeforeRender()<seq2seq4repair_space>in<seq2seq4repair_space>the<seq2seq4repair_space>override<seq2seq4repair_space>of<seq2seq4repair_space>onBeforeRender()<seq2seq4repair_space>method" ) ) ; } } } public final boolean continueToOriginalDestination ( ) { } public final void debug ( final String message ) { } public final void detach ( ) { } public final void detachBehaviors ( ) { } public void detachModels ( ) { } public final void error ( final Serializable message ) { } public final void fatal ( final String message ) { } public final MarkupContainer findParent ( final Class c ) { } public final MarkupContainer findParentWithAssociatedMarkup ( ) { } public final Application getApplication ( ) { } public final List getBehaviors ( ) { } public final String getClassRelativePath ( ) { } public final IComponentBorder getComponentBorder ( ) { } public final IConverter getConverter ( ) { } public IConverter getConverter ( Class type ) { } public final boolean getEscapeModelStrings ( ) { } public final FeedbackMessage getFeedbackMessage ( ) { } public String getId ( ) { } public final IModel getInnermostModel ( ) { } public Locale getLocale ( ) { } public final Localizer getLocalizer ( ) { } public final ValueMap getMarkupAttributes ( ) { } public String getMarkupId ( ) { } public final Serializable getMetaData ( final MetaDataKey key ) { } public final IModel getModel ( ) { } public final Object getModelObject ( ) { } public final String getModelObjectAsString ( ) { } public final String getModelObjectAsString ( final Object modelObject ) { } public final boolean getOutputMarkupId ( ) { } public final Page getPage ( ) { } public final IPageFactory getPageFactory ( ) { }

Fix:
if ( ( ( isVisible ( ) ) && ( ! ( getFlag ( Component . FLAG_RENDERING ) ) ) ) && ( ! ( getFlag ( Component . FLAG_PREPARED_FOR_RENDER ) ) ) ) {